/*
*    Qizx/open 3.0 beta
*
* This code is the open-source version of Qizx.
* Copyright (C) 2004-2009 Axyana Software -- All rights reserved.
*
* The contents of this file are subject to the Mozilla Public License 
*  Version 1.1 (the "License"); you may not use this file except in 
*  compliance with the License. You may obtain a copy of the License at
*  http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
*  WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
*  for the specific language governing rights and limitations under the
*  License.
*
* The Initial Developer of the Original Code is Xavier Franc - Axyana Software.
*
*/
using System;
using System.Qizx.Api;
using EvaluationException = System.Qizx.Api.EvaluationException;
using EvalContext = System.Qizx.XQuery.EvalContext;
using Focus = System.Qizx.XQuery.Focus;
using XQType = System.Qizx.XQuery.XQType;
using XQValue = System.Qizx.XQuery.XQValue;
namespace System.Qizx.XQuery.Fn {

    /// <summary>  Implementation of function fn:string-join.</summary>
    public class StringJoin : Function {
        public override Prototype[] Protos {
            get {
                return protos;
            }

        }
        internal static Prototype[] protos;

        public class Exec : Function.StringCall {
            public override string evalAsString(Focus focus, EvalContext context) {
                context.at(this);
                XQValue v = args[0].eval(focus, context);
                string sep = args[1].evalAsString(focus, context);
                System.Text.StringBuilder buf = new System.Text.StringBuilder();
                bool first = true;
                for (; v.Next(); ) {
                    if (!first)
                        buf.Append(sep);
                    first = false;
                    XQItemType itemType = v.ItemType;
                    if (itemType == XQItemType.STRING || itemType.IsSubTypeOf(XQItemType.STRING) || itemType == XQItemType.ELEMENT) {
                        buf.Append(v.ValueAsString);
                    } else {
                        context.error(System.Qizx.XQuery.Op.Expression.ERRC_BADTYPE, this, "fn:string-join(xs:string*) found a " + v.ItemType + " typed member.");
                    }

                }
                return buf.ToString();
            }
        }
        static StringJoin() {
            protos = new Prototype[] { Prototype.fn("string-join", XQType.STRING, typeof(Exec)).arg("op1", XQType.STRING.star).arg("op2", XQType.STRING) };
        }
    }
}